Heat dissipation device with guiding line and soldered heat pipe

ABSTRACT

A heat dissipation device with guiding line and soldered heat pipe includes a heat pipe and a heat sink. The heat pipe includes a condenser section and an evaporator section. The condenser section has a planar outer surface. The heat sink includes a supporting surface contacting the outer surface of the condenser section. A guiding line is defined in the supporting surface for spreading solder therealong. The guiding line has a width smaller than a width of the outer surface of the condenser section. The condenser section of the heat pipe is mounted on the supporting surface of the heat sink along the guiding line and firmly connected to the heat sink by the solder.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional application of patentapplication Ser. No. 12/558,602, filed on Sep. 14, 2009, entitled “HEATDISSIPATION DEVICE WITH GUILDING LINES AND SOLDERED HEAT PIPES ANDMANUFACTURING METHOD THEREOF,” which is assigned to the same assignee asthe present application, and which is based on and claims priority fromChinese Patent Application No. 200910304299.9 filed in China on Jul. 13,2009. The disclosures of patent application Ser. No. 12/558,602 and theChinese Patent Application are incorporated herein by reference in theirentirety.

BACKGROUND

1. Technical Field

The disclosure relates to heat dissipation, and particularly to a heatdissipation device for dissipating heat generated by an electroniccomponent.

2. Description of Related Art

Electronic components operating at high speed generate excessive heatwhich must be removed efficiently to ensure normal operation. Typically,a heat dissipation device attached to the electronic component providessuch heat dissipation.

A conventional heat dissipation device includes a heat sink and a heatpipe connected to the heat sink. The heat pipe is linear shaped and hasa rectangular planar bottom surface for contacting a side surface of theheat sink. When the heat pipe is combined to the heat sink, a solderlayer is spread on a portion of the side surface of heat sink by anoperator for fixing the bottom surface of the heat pipe thereon.

However, a position of the solder layer is decided by visual observationof the operator, and the solder layer usually has an irregular shape andan imprecise location. When the bottom surface of the heat pipe isattached to the heat sink, a part of the bottom surface of the heat pipemay directly contact a portion of the side surface without solder spreadthereon, and thus the connection between the heat pipe and the heat sinkis faulty. Furthermore, a portion of the solder layer uncovered by thebottom surface of the heat pipe may melt during soldering and flow toother portions of the side surface uncovered by the bottom surface ofthe heat pipe, thereby contaminating the heat sink. This results inwaste of the solder and trouble required to clean the contamination.

It is thus desirable to provide a heat dissipation device which canovercome the described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a heat dissipation deviceaccording to an exemplary embodiment.

FIG. 2 is an exploded view of the heat dissipation device of FIG. 1.

FIG. 3 is an enlarged view of a circled portion III of FIG. 2.

FIG. 4 is a view schematically showing solder layers being formed on asupporting surface of the heat sink along guiding lines thereof.

DETAILED DESCRIPTION

Reference will now be made to the drawing figures to describe thepresent heat dissipation device and a manufacturing method thereof indetail.

FIG. 1 illustrates a heat dissipation device for dissipating heatgenerated by an electronic component (not shown). The heat dissipationdevice includes a heat sink 10 and two heat pipes 20.

Referring to FIG. 2, each of the heat pipes 20 is tubular, and includesan evaporator section 22 and an opposite condenser section 24. Thecondenser section 24 of each of the heat pipes 20 is linear shaped, andhas a rectangular planar bottom surface 240.

The heat sink 10 includes a plurality of first fins 11 and a pair ofsecond fins 12. The first fins 11 are located at a central portion ofthe heat sink 10, and the pair of second fins 12 are arranged at leftand right sides of the first fins 11, respectively. The first and secondfins 11, 12 are arranged side by side along a left-to-right direction ofthe heat sink 10. Each of the first and second fins 11, 12 includes aplate-shaped main body 120, a bottom flange 122 extending leftwards andperpendicularly from a bottom side of the main body 120, and a topflange 125 extending leftwards and perpendicularly from a top side ofthe main body 120. A top side of a middle portion of each main body 120in a front-to-rear direction is lower than top sides of front and rearportions of the main body 120. Accordingly, a rectangular groove 18 isdefined in a middle portion of the heat sink 10 between front and rearportions of the heat sink 10 after the first and second fins 11, 12 arestacked together.

Each of the top flanges 125 includes two upper flange portions 124formed at the top sides of the front and rear portions of thecorresponding main body 120, respectively, and a lower flange portion126 formed at the top side of the middle portion of the correspondingmain body 120. The main bodies 120 of the first and second fins 11, 12are parallel to and equally spaced from each other. Each of the top andbottom flanges 125, 122 has a width substantially equal to a distancebetween the main bodies 120 of neighboring fins 11, 12. Each of the topflanges 125 extends perpendicularly from the top side of the main body120 to contact the main body 120 of a neighboring fin 11, 12. Thus theupper flange portions 124 of the top flanges 125 cooperatively form twoplanar top surfaces 16 at top sides of the front and rear portions ofthe heat sink 10, respectively. The lower flange portions 126 of the topflanges 125 cooperatively form a supporting surface 19 at a top side ofthe middle portion of the heat sink 10. In addition, the bottom flanges122 of the fins 11, 12 cooperatively form a planar bottom surface 14 ata bottom side of the heat sink 10.

Referring to FIGS. 2 and 3, front and rear cutouts 150, 151 are definedin front and rear ends of each of the lower flange portions 126 of thefirst fins 11, respectively. The front and rear cutouts 150, 151 of eachof the lower flange portions 126 are parallel to each other. Each of thecutouts 150, 151 extends along a bending direction of the lower flangeportion 126, and is perpendicular to the main body 120. Each of thecutouts 150, 151 has a length in the left-to-right directionsubstantially equal to the width of the lower flange portion 126, and adepth slightly smaller than a thickness of the lower flange portion 126.Thus each of the cutouts 150, 151 extends through left and right sidesof the lower flange portion 126. The front cutouts 150 of the lowerflange portions 126 of each two neighboring first fins 11 arecommunicated with each other. More specifically, for each twoneighboring first fins 11, a right end of the front cutout 150 of a leftfirst fin 11 connects a left end of the front cutout 150 of a rightfirst fin 11. Thus a first guiding line 15 is formed at a front end ofthe guiding surface 19 of the heat sink 10 by the front cutouts 150 ofthe lower flange portions 126 after the first fins 11 are stackedtogether. Similarly, the rear cutouts 151 of the lower flange portions126 of each two neighboring first fins 11 are communicated with eachother, and a second guiding line 15 is formed at a rear end of theguiding surface 19 of the heat sink 10 by the rear cutouts 151 of thelower flange portions 126 after the first fins 11 are stacked together.

When the heat sink 10 is assembled, the first fins 11 are arranged atthe central portion of the heat sink 10 side by side, and the secondfins 12 are arranged at the left and right sides of the first fins 11,respectively. The first and the second guiding lines 15 are accordinglyformed by the front and rear cutouts 150, 151 of the first fins 11 atthe front and rear ends of the guiding surface 19, respectively. Each ofthe guiding lines 15 extends straightly as does the bottom surface 240of the condenser section 24 of a corresponding one of the heat pipes 20,and each guiding line 15 has a width much smaller than a width of thebottom surface 240 of the condenser section 24 of the corresponding heatpipe 20. Since the second fins 12 do not define cutouts therein and thelower flange portions 126 of the second fins 12 each have completelysmooth top and bottom faces, each of the guiding lines 15 forms closedends 152 at left and right ends thereof, respectively. That is, each ofthe guiding lines 15 does not extend through the left and right sides ofthe heat sink 10, and the closed ends 152 of each guiding line 15 areadjacent to the left and right sides of the heat sink 10, respectively.

Referring to FIG. 4, an amount of solder is spread on the supportingsurface 19 along the first and second guiding lines 15 to form twostraight rectangular solder layers 30 respectively. Each of the solderlayers 30 has a size not larger than a size of the bottom surface 240 ofthe corresponding condenser section 24. In this embodiment, the size ofeach of the solder layers 30 is substantially equal to the size of thebottom surface 126 of the condenser section 24. Then the heat pipes 20are positioned on the supporting surface 19 of the heat sink 10, withthe bottom surfaces 240 of the condenser sections 24 contacting thesolder layers 30, respectively. Finally the heat pipes 20 are solderedto the heat sink 10 by heating the solder layers 30.

Since the guiding lines 15 are provided on the supporting surface 19 ofthe heat sink 10, the solder can be conveniently spread on correctpositions of the supporting surface 19 along the guiding lines 15 toform the straight, rectangular solder layers 30 on the supportingsurface 19. Thus the heat pipes 20 can be accurately mounted to thesolder layers 30 of the supporting surface 19, and good contact isformed between the heat pipes 20 and the supporting surface 19.Furthermore, since the guiding lines 15 form the closed ends 152 at theleft and right ends thereof, when the solder is heated, molten solderwill not flow from the guiding lines 15 to the left and right sides ofthe heat sink 10 to contaminate the heat sink 10. Moreover, the moltensolder has a tendency to expand and overflow when heated. The guidinglines 15 can provide a space for receiving the expanded molten soldertherein, thereby avoiding the molten solder flowing from the solderlayer 30 to other portions of the supporting surface 19 to contaminatethe heat sink 10. Thus, the solder between the heat pipes 20 and theheat sink 10 forms a firm connection between the heat pipes 20 and theheat sink 10.

It is to be understood, however, that even though numerouscharacteristics and advantages of the embodiment have been set forth inthe foregoing description, together with details of the structures andfunctions of the embodiments, the disclosure is illustrative only, andchanges may be made in detail, especially in matters of shape, size, andarrangement of parts within the principles of the invention to the fullextent indicated by the broad general meaning of the terms in which theappended claims are expressed.

What is claimed is:
 1. A heat dissipation device comprising: at leastone heat pipe comprising a condenser section and an evaporator section,the condenser section having a planar outer surface; and a heat sinkcomprising: a supporting surface for contacting the outer surface of thecondenser section, at least one solder layer being formed in thesupporting surface, the at least one solder layer being a first groovefilled with solder, which is spread on the supporting surface, the atleast one solder layer having a width smaller than a width of the outersurface of the condenser section, the condenser section of the at leastone heat pipe being mounted on the supporting surface of the heat sinkalong the at least one solder layer and firmly connected to the heatsink by the at least one solder layer; and a plurality of fins arrangedside by side, each of the fins comprising a main body and a flangeextending perpendicularly from one side of the main body to contact themain body of a neighboring fin, at least one cutout being defined in anouter surface of the flange of each fin, the at least one cutouts of theflanges cooperatively forming the at least one first groove; wherein aheight of a middle portion of the main body is smaller than a height offront and rear portions of the main body, the flange comprising twoupper flange portions at top sides of the front and rear portions of themain body respectively and a lower flange portion at a top side of themiddle portion of the main body, the lower flange portions cooperativelyforming the supporting surface of the heat sink, a second groove beingdefined in a middle portion of the heat sink above the supportingsurface and receiving the condenser section of the at least one heatpipe therein, the second groove spanning the entire width of all theflanges of all the fins; and wherein the heat sink further comprises twoend fins, one of the end fins is arranged side by side with an endmostfin of the plurality of fins, the other end fin is arranged side by sidewith an opposite endmost fin of the plurality of fins, and each of theend fins is substantially the same as each of the plurality of finsexcept that the end fin does not have the at least one cutout defined inthe outer surface of the flange thereof.